Structural evolution during micelle polymerization

The evolution of microstructure during the free-radical polymerization of the surfactant cetyltrimethylammonium 4-vinylbenzoate has been measured using small-angle neutron scattering. The polymerization of the micelles was performed online, collecting SANS data continuously during the polymerization. Unlike microemulsion polymerizations, this micellar polymerization is seen to proceed through a highly turbid phase with local, short-range order at a length scale of approximately 50 Å. A simple structural model has been proposed to quantify the structural changes during the course of the reaction. The ordered structure is postulated to be an ordered bundle of cylindrical micelles, which subsequently breaks up into the final equilibrium structure of discrete, polymerized cylinders.